My digital 'audiophile' set up is in my office at work. It is actually my best sounding system and I was quite surprised by that.

Win7 machine feeding MP3's and Flac to a

HRT Musicstreamer II+ DAC

into a 70's era Pioneer SX3700 receiver

then through a pair of Martin & Logan Motion 4 speakers and a small sub.

I expected pretty good sound. The tweeters in the Motion series are amazing. But I got great sound. Wide detailed sound stage with actual depth. Closing my eyes and sitting back results in a perceived tripling of the size of my office.

I'm in the process of adding a Mac Mini at home to serve music and movies to my home theater. I also hope to be able to rip LPs from my analog only stereo set up. Thinking/hoping I can use garage band to do so. Eventually reducing my system down to the single HT receiver at home. Too many systems in my little apartment right now. _________________Hey Ma! Watch this!

I don't see the point of using a Mac Mini as the source of an audiophile setup, if that would be its primary use.

Not a single component of the Mini is usable, so you basically have to just transport the digital signal through HDMI or optical to an external DAC, next to an audiophile grade (headphone) amp.
You can use an Apple TV, or an iPad with USB camera connector for that purpose too._________________Mac mini 2,1 2.33Ghz C2D with 1TB 12mm internal HDD / 2GB RAM / Broadcom Crystal HD Mini PCIe
Apple TV with 500 GB HDD / Broadcom Crystal HD Mini PCIe
i7 iMac / 12GB RAM
Denon AVR-3312 with Airplay